1. Field of the Invention
The present invention relates to an injection molding die for producing a resin molded body having a design surface and a method for producing a resin molded product using the die. A metal plating layer is formed on the design surface of the resin molded body molded using the injection molding die of the present invention.
2. Description of Related Arts
Many members having a metal plating layer, such as an ornament, a grill, a wheel cap, a resistor and a bumper are used in automobiles. Such members are produced by preparing a resin base material, for example, by injection molding and applying plating of a metal such as chromium to its design surface. While metal plating is carried out by electroplating, the resin base material is an insulator in many cases, and thus is often difficult to undergo electroplating.
Therefore, electroless plating is applied to a resin base material to form an electrically conductive metal layer made of nickel or the like, and electroplating is then carried out. Alternatively, electroplating is carried out by a plating direct process with electroless plating treatment being omitted.
However, the adhesion of a plating film to a resin molded body becomes problematic in many cases, and thus various methods have been proposed in order to improve the adhesion. For example, JP 2011-063855 A describes a method including treating a resin base material with an ozone solution to form a surface-modified layer, giving energy such as plasma to remove a surface layer of the surface-modified layer, and thereafter applying electroless plating thereto.
JP 2007-327131 A describes a method including treating a surface of a resin base material with a pretreatment solution containing an anionic surfactant and an organic solvent, treating the base material with a noble metal ion-containing treatment liquid containing an anionic surfactant and noble metal ions, subjecting the plated material to heating treatment, treating the heat-treated material with an aqueous alkaline solution, and thereafter applying electroless plating treatment thereto.
According to these methods, the adhesion of a plating film is improved without using a harmful substance such as chromic acid.